Friction clutch



Patented Nov. '1, 1938 UNITED .STATE `s PATENT oFFi'c-E N FBICTION CLUTCH Channing E. Harwood, Middletown, Conn., as-

signor to The Russell Manufacturing Company,

VMiddletown, Conn., a corporation Application october 2,4, 1934, sensi No, "149,140

Another object of this invention is to provide J ansimproved method of frictionally clutching 7two complementary members' together to avoid L roughness, grabbiness,` chatter and `wear.

.1b 'from roughness, grabbiness and chatter.

lu With the above and other objects in view,

- this invention includes all improvements' over the prior art which are disclosed in this applicatiom In the accompanying drawings, in which cer' gmtain 'ways ofscarrying out the invention vare.

- shown for illustrative purposes:

Fig. 1 is a front elevation illustrating one embodiment of a clutch-friction disk or facing made in accordance with this invention, and having 25 two concentric-rings of different friction-cosm- *a cients;

Fig. 2 is a .view similar to Fig. 1,- of a modifled-form of clutch-friction disk or facing in which the locations of the concentric-rings of different' friction-coefficients are reversed as compared to their locations in Fig. 1;'

iig. 3 is a view similar to Fig. '1, of amendi-A fled form of clutch-iriction disk or facing having a larger number of concentric-rings of dif- 35. ferent friction-coefficients;

Fig. 4 is a sectional view of a friction-clutch having a distortable-dished plate-like carrier, on the opposite faces of which arev secured fric- "tion-disks of the type shown in Figs. 1 and 2; 40 with the clutch disengaged;

Fig. 5 is a view similar to Fig. 4, but with the clutch engaged;

Fig. 6 is an exaggerated edge elevation showingI a dlstortable or fiattenable oppositely-un- 45 dulated plate-like carrier having a clutch-friction disk orfacing on each of the opposite faces thereof, and adapted for use in place -of the distortable dished plate-like portion of the construction shown in Fig. 3, each friction-disk hav- 50mg dierent segmental areas of different fric tion-coefficients; e

Fig. 'l is a front elevation of a clutch-friction disk like those shown in Fig. 6;

Fig. 8'is a view similarto Fig. 7, showing a 55 modified form of clutch-friction disk or facing (ci. 19a-1m) lhaving a larger number of segmental areas of different friction-coefficients;

Fig. 9 is an enlarged sectional view on the line 9 -9 of Fig. 1;

"Fig, 10 is a sectional view illustrating a modi- 5 ned form of the construction shown in Fig. 9; and

Fig. 11 is la. sectional Iview of a portion of a modified form of'clutch-disk of the type shown in Fig. "l, but made of woven fabric, with theA 10 parts thereof in exaggerated relation f or clearness, the section being on an enlarged scale and taken at'a place similar to that indicated byline II-H of Fig. '7.

vIn thedescription and claims, the various parts 15 and steps are 'identified by specific names for convenience', but they are intended to be as generic i-ntheirfapplication as the prior art `will permit. i

In the form o'f.the invention illustrated in 20 Fig. i, the enrich-friction disk or facing zo has outer andinner rings 2l and 22 of different friction-coeicients, the outer ring 2| having a lower coefllcient of friction .than the inner ring 22.`

1n the form of the invention iuustrated in Fig. 25sh 2, the friction-disk 23 has an outerring 24 of .higher friction-coeiilcient than the inner ring 25.

In the form `of the invention illustrated in Fig. .3, the friction-disk 26 has a comparatively large number of rings 21, 28, 29, 30, 3|, 32, of -30 successively higher coeiiicients of frictionfrom ring 21 to ring 32 inclusive. Thus, the frictiondis'k 26 isofj a similar type to the friction-disk 23' (Fig. 2) but with .the disk formed of a larger number of rings, whereby each two successive rings may have friction-coe'mcients differing but slightly from each other .and thus provide a vsubstantially continuous variation of friction-coefficient from the outer to the inneredge of the disk. 'rhenumber of the rings in the disk 2 6. 4o` can be made greater or less, as'desirable. Disks like disk 26 but with the fctloncoefilcients arranged in the reverse order can be made to cor-'- respond tothe arrangement of rings in the disk 20 v.(Fig. 1). y 4'5 The friction-disksformed of concentric-rings of different friction-coefficients as shown in Figs.

1, 2 and 3, may be made in various ways. The concentric-rings of separate members may be joined in abutting relation as shown in Fig. 9, or, in addition to being formed in abutting relation, they may have a backing-strip 33 (Fig. 10)

, secured to the back of the friction-member inV any suitable way.

In ypmdusing this difrun friction-doemsii,l

xao

A separate rings, they may be formed integral by v cient or multi-tone effect on the felted or molded type by combining two or more rings of different s friction-coelcients, the following procedure can be followed, for example: If it is desired to make a dual friction-coeiiicient ring 9%"x61/8x%", a ring 9%"x3%"xf" may be cut from stock having a friction-coeflicient of, say, .20, under a given set of conditions.` This stock may, for example,

have been previouslytreated but not cured with a synthetic resin. A ring 91%4"x6%"x" may next be cut from a rubber formulation, and having a friction-coeiiicient of. say, .30, under the same conditions as the first ring. 'I'he two ringsfacing to the opposite faces of the plate-like car-I- river or member 34 (Figs. 4 and 5), the rivet-holes may be so placed as to prevent slippage between the two rings. This can be accomplished either by having rivet-holes extending through each of the two rings or by having rivet-holes extending through equal portions of the two rings through the junction of the latter.

Instead of forming the friction-members of placingplain, untreated rings upon a suitable arbor witha -spacer between each ring to permit easy access for treatment. This arbor may then l'be dipped to a predetermined depth in a suitable compound, and rotated slowly therein. For such compounds, a solution comprising a non-oxidizing oil, a high melting point wax, or other suitable friction-reducing ingredients may be em- 'Vployed to produce a friction-member having differential friction-coeicients of the nature of the friction-member illustrated` in Fig. l. Or, conversely, in order to produce a'friction-member of the form shown in Fig. 2, with the outer ring ofhigher friction-coemcienhan asphalt, a rosin oil, or gilsonite in a. suitable solvent may be used to raise the friction over that obtained with the treatment customarily employed to produce a given friction-member'or facing of`a single friction coemcient.

Another wry of making friction-facings of the type' shown in Figs. 1 and 2 is by means of 'using solid, woven tapes or bands, woven, for example,v from asbestos yarn, preferably having a wire core. The tape is woven in the conventional manner. One .edge portion of thetape may then be painted, dipped or otherwise impregnated with a compound that will produce a friction-ccedicient lower than that given by the conventional treatment. The tape will then be saturated with water and wound on an annular mandrel and formed into a helix, and will be dried, cured and finished in the conventional manner, vand then given a cut to separate the helix into a plurality of split-ring members of the general appearance of Figs. l and 2, except that they will have a split through one side, the adjacent edges of which can be connected together in the usual -way. In'

finished thickness, the renewing is steuer method: suitable number of warp threads, de-

pending upon the width of the lower friction area binder threads through a friction-reducing compound contained in a suitable pan attached to the loom, thus doing away with an additional# operation. They advantage of this method over the method of dipping the edge portion of a will be readily apparent for obtaining this multitone or multi-friction effect in woven clutch-disks material having a different coemcien.. of friction from that used in the balance of the tape. By treating a plurality of groups of warp and binder threads to give them a corresponding plurality of different coeicients ofA friction, woven friction-disks of the type shown in Fig. 3 can be made. i

In theconstruction shown in Figs. .4 and 5, 34 is a distortable, dished, plate-like carrier or member which is secured by bolts 35 or otherwise to a hub 36. Secured to opposite faces 3l and 38 of the member 34 are friction-members or facings and 23. The friction-member 20 has the concentric-rings 2| and 22 of different coefficients of friction, and the friction-member 29 has the concentric-rings 24 and 25 of different coeilicients of friction. The rings 2| and 25 may have one coeiiicient of friction, while the rings 22 and 24 have another coemcient of friction. The carrier 34, with the friction-disks 20 and 23, is between the pair of rotary members 39 and 40, which are splined for relativemovement toward and from each other to compress and distort or straighten out the dished plate-like carrier, for example, to bring about desired clutching or coupling action between two complementary members such asr a flywheel 39 and 40 and a driving-hub 36.

Where the driven-member of a clutch or other friction coupling-device shows a roughness, grabbiness or chatter in the initial stages of its engagements, th ring-portions 2| and 25 will preferably be of relatively-low coelcient of friction,

whereas the ring-portions 22 and 24 will be of relatively-high coefficient of friction. Thus, when the rotary members 39 and 40 approach relatively toward one another, the dished platelike carrier 34 carrying the friction-disks' 20 and 23 will be distorted "or flattened out during the progressive relative movement of members 39 and 40 toward one another, so that, initially, the

-gaged in addition to the rings 2| and 25, the

ring-portions 22 and 24 being of relatively-high friction-coefllcient. -With other types of frictional coupling-devices, the reverse may be true, that is, where rough action is experienced in the final stages of engagement.- Itfwill be obvious that in this instance, the position of the high and low friction-coefiiclent ringswould be re- 20 such, for instance, -as substitutinga strand of aromas Vlong slip period. In actual practice, with some types of undulated, plates or carriers, it has been found that owing to the. limited space available for the driven-member, it is impossible to provide sufiicient oilset or undulation without causing Y serious drag. This makes it diillcult or -impossible to shift the gears on an automobile, for example, employing this construction, and subjects the clutch-facings to abnormally high wear.

The undulated plate-like carrier 4i is secured to a hub 36 in a similar manner to that illustrated in Figs. 4 and 5 and carries upon its opposite faces two friction-disks or facings 42 and 43.

The high or convex portions 44 of the frictionfacings 42, 43, have one friction-coefficient, While the .low or concave portions 45 of thefrictionfacings 42, 43, will have a different frictioncoeillclent. When it is desired that the initial engagement shall be one employing low frictioncoeilicient, in a manner similar to that described concerning the form of construction shown in Figs.' 4 and 5,then the convex or high portions 44 will be of relatively-low friction-coefficient, while the low or concave portions 45 will be of relatively-high friction-coeilcient, sothat when the form of construction shown in Figs. 6 and is employed in connection with cooperating coupling-members such' as 39 and 40, the manner 'of operation by which the parts '39 and 40 will rst engage the highportions 44, will then a-tten or distort the disk 4i to`also bring into frictional engagement the low portions 45. The segmental portions 44 and. 45 are of sector shape in the particular form of the inventionherein disclosed.

In the form of the invention illustrated in Fig. 8, the friction-disk 46 has segmental portions 41, 48, 49, 50, 5I, 52 of successively higher coefilcients of friction from segmental portion 41 to vsegmental portion 52 inclusive. friction-disk l45 is of a similar type to frictiondisk 42 (Figs. 6 and 7) but with the disk formed of a larger number' of segments or segmental portions whereby each two successive segments may have friction-coeflicients differing but slightly from each other and thus provide a substantially continuous variation of friction-coemcient from each of the segments 41 to segments 52.

The number of the segments in the disk 46 can be made greater or less as desirable. mental portions 41 to 52 are sector shaped in the particular form of the invention herein disclosed.

By providing clutch-frictiondisks or facings which have properly-arranged distinct areas Aof relatively-low friction-coefficient and less'grabbing eiect and high wear-resistance, together with areas of relatively-high friction-coefcient with consequent high grabbing effect, though possibly of lesser wear-resistance, a very superior and I long-lived clutch may be constructed by properly installing such facings. For instance, if the friction-facings are sci-arranged in a clutch-structure that the surfaces of relatively-low friction- `coeilicient engage rst, while the relative motion between the parts of theclutch is greatest, such Thus, the

The seg-v engagement will eect a smooth-acting tendency to bring the parts ofthe clutch into synchronism without a grabbing effect, and will be able to withstand to the maximum degree, the wear incident to their engagement when the parts of the clutch are moving relatively at maximum speed.

, Then. by having the surfaces of relatively-highl friction-coefficient next brought into action, the relatively-moving parts of the clutch will have been brought more nearly into synchronism and the tendency of the latter friction-surfaces' to occasion 4a grab', will be negligible and the Wear imposed on the said surfaces 'of relatively-high friction-coeiiicient `,(and hence, lesser wear-resistance) will be minimized by the previous action of the first-mentioned surfaces of relativelylow friction-coefficient, which have discharged a preliminary task of, partially at least, synchronizing the parts of the clutch as above described.

In the form of the invention illustrated in Fig. 11, a disk 53 is formed from a Woven band having two plys 54 and 55 of asbestos yarn, for

example, which plys are alternately passed back and forth to form areas which extend entirely across the band and of substantial length.- By making the ply 54 from a yarn having one coeiiicient of friction, and the ply 55 from yarn having another coefficient of friction, itis thus possible -to have the face areasr 54 ofdifierent coefiicient of friction from', the face areas 55. The manner of Weaving and alternately crossing the plys 54 and 55 back and forth., to and from the opposite faces of the band 53 and connecting the plys by the binder threads 56, is known to those skilled in the art. The manner of making one of the plys of different coeicient of friction from the other ply can be accomplished in various Ways, one way being to impregnate the thread to be used for one of the plys with a suitable mixture such, for example, as graphite, talc` and light mineral oil, as heretofore more particularly described, in connection with using woven facings of the form shown in Figs. 1 and 2. By winding the woven band into a helix and cutting the helix into rings and subjecting them to the other usual finishing processes, as previously described convcerning Figs.` 1 and 2, a clutch-disk or facing with differential areassuch as illustrated in Figs. 6 and 7, is produced.

Friction-disks when made in accordance with this invention, to have different friction areas of different friction-coeiiicients. have high resistance to Wear and tend to minimize or eliminate roughness, grabbiness or chatter. And when friction-disks made in accordance with this invention are employed in the way described in connection with Figs. 4, 5, 6 and '1, roughness, grabbiness and chatter are eliminated with even greater certainty. l

The invention may be carried out in other specific ways than those herein set forth without.

departing from the spirit and essential characfriction-face with different sectoral friction areas side by side circumferentially of the disk and of substantially-different frlction-coeicients.

2. A clutch-friction disk distortable in direceach of said segmental areas extending radially substantially-entirely acrossthe friction-disk.

3. A clutch-friction disk havingv a friction- ,face with separated sectoralfriction areas of different friction-coefficients, and one or more sec- 10 toral areas of friction-coeiilcient or coemcients intermediate the friction coefficients Vof said sep- .larated sectoral friction areas and located between Y said separated sectoral friction areas.

4. A clutch-friction disk having a friction-face with separated segmental friction areas of differet l fr iction-coenicients, and one or more seglfmental areas of friction-coefdcient or coefficients intermediate the friction-coeihcients of Mid separated segmental friction areas and located between said separated segmental friction areas, each of said segmental areas extending radiallyv substantiallyentirely across the friction-disk.

v5.' A friction-clutch including in combination:

Atwo complementary members to be frictionally vcoupled together; a. distortableplate-like carrier, and a'friction-member mounted on said carrier and having different friction areas of substantially-diiferent friction-coeflcientsi and means for distorting said carrier and successively frictionally engaging the differential friction areas of the said friction-member with one of the said complementary members, the friction areas which first engage being of one friction-coefficient and' the friction areas which later` engage being of a different friction-coeflicient.

s carrier, and a friction-member mounted on ls'aid carrier and having different concentric frictionrings of substantially-different friction-coeficients; and means for distorting said carrier and successively frictionally engaging the differential concentric friction-rings of the said frictionmember with one `of the said complementary members, the rings which first engage being of one .friction-coefficient and the rings which later engage being of a different,friction-coefficient.

7.A friction-clutch including in combination: two complementary members to be frictionally coupled together; a distortable undulated platelike carrier, and a frictionLn-.ember mounted on said carrier and havingdifferent friction areas substantiallydifferent friction-coeiilcients; and means for distorting said carrier and successively frictionally engaging the differential friction areas of. the said Afriction-member with one of the said complementary members, the

friction areas which first engage' being of one friction-coefilcient and the frictionareas which later engage being of a different friction-cueill- 8. A friction-clutch including in combination:

'two complementary members to be frictionally coupled together; a distortable, dished, plate-like member carried by one of said complementary members; a pair of friction-memberaonesecured to each-of opposite; faces of said plate-like carrier; each friction-member having outer and inner rings of substantially-different friction-coefficients, the friction-coemcients of the outer and inner rings on one face corresponding, respeccarrier; and means to distort said plate-like car- ,Y

i which later engage "arcaico rier and rstcause an outer ring on one face andan inner ring on the other face, and then cause an inner ring on said one face and an outer ring on-said other face, of said plate-like carrier,

` to frictionally engage with the other of said complementary members.

9. A friction-clutch including in combination; two complementary members `to be frictionally coupled together; a fiattenable,y oppositely-undulated, plate-like carrier carried by one of said complementary membersffa pair of frictionmemberaonesecured to each of opposite faces of said plate-.like carrier; each friction-member considerable width in a direction radially across the friction-member and arranged annularly about the friction-member with the friction areas on the opposite high portions of the platesaid plate-like carrier, to frictionally engage with the other of said complementary members.

10. A friction-clutch including in combination:- two, complementary members to be frictionally coupled together; a distortable, dished, plate-like member carried by one of said complementary members; a pair of friction-members, one secured to each of opposite faces of said plate-like carrier; each friction-member having outer and y inner rings of substantially-different friction-coefficients the friction-coefficients of the outer andiinr'i'eizirings on one face corresponding, re-

spectively, to the friction-coefficients of the inner and outer' rings on the other face, of said platelike carrier; and means to distort said plate-like 1 said complementary members, the rings which first engage being of relatively-low friction-ccedicient and the rings which later engage being of relatively-high friction-coefficient.

1i. A friction-clutch including in combination:

'two complementary members to be frictionally coupled together; a iiattenable, oppositely-undulated, plate-like carrier carried by one of said complementary members; a pair of friction-members,one secured to each of opposite faces of said plate-like carrier; each friction-member having -friction areas of substantially-different frictioncoefficients, the friction areas being of consider'- a'blewidth in a direction radially across the fric.-

tion-member and arranged annularly about the vfriction-member with the friction areas on the opposite high portions of the-plate-like carrier of substantially-diiferent friction-coemcient from the friction areas on the opposite low portions 'l of the plate-like4 carrier; and means toflatten said -plate-like member andrnrst cause the friction areas on said high portions andy then cause the friction areas on said low portions, of said plate-like carrier, to frictionally engage with the other of said complementary members, the friction areas which-first engage being of relativelylow friction-coefficient and the friction areas @g of relatively-highfriction-coeilicient.

12. A manon member comprising a disk hdvf ing mounted upon a face thereof a plurality of durability and relatively-low coemcient of friction.

14. A friction member comprising a disk having mounted on both faces thereof a plurality of sectoral friction portions of different frictional characteristics, portions having one set of frictional characteristics being alternately spaced and interspersed between portions having another set of frictional characteristics, and the portions having one set of frictional characteristics positioned on one face of the disk being disposed opposite those positioned on the other 'face of the disk having another set of frictional characteristics.

15. A friction member comprising a disk having mounted upon a face thereof a plurality of sectoral friction portions of different types, one comprising a material having characteristics of relatively-low durability and relatively-high coefllcient of friction, and another having characteristics of relatively-high durability and relatively-low coelcient of friction.

n 16. A friction clutch including in combination,

two complementary members to be frictionally coupled together, a distortable plate-like carrier, and a plurality of sectoral friction elements mounted on said carrier having different ooeillcients of friction, and means for distorting said carrier and successively frictionally engaging the diierent friction elements with one of said complementary members, the friction elements which irst engage being of one friction. coefficient and the friction elements which later engage being of a different friction coefficient.

17. A friction clutch including in combination, two complementary members to be frictionally coupled together, a distortable offset plate-like carrier, and a plurality of friction elements mounted on said carrier of substantially-differ- 'ent friction coefcients, and means for successively frictionally engaging the differential friction elements with one of said complementary members, the friction elements which first engage being of one friction coefficient, and the friction elements. which later engag'e being of a different friction coeihcient.

18. A friction clutch including in combination, two complementary members to be frictionally coupled together, a iiattenable, oppositely-oifset, plate-like carrier carried by one of said complementary members, friction portions secured to each face of said plate-like carrier. said friction portions being of substantially-different friction coemcients, the friction portions being of -considerable width in a direction radially across the friction portions and arranged annularly .about the plate-like carrier, with friction portions on the opposite high portions of the plate-like carrier of substantially-different friction coefhcient from the friction portions on the opposite low portions of the plate-like carrier, and means to flatten said-plate-like member and first cause the friction portions on said high portions and then cause the friction portions on said low portions, of said plate-like carrier, to frictionally engage with the other of said complementary members.

CHANNING E. HARWOOD. 

